Methods for diagnosing and treating eosinophilic esophagitis

ABSTRACT

Disclosed are methods of diagnosing and treating a subject with active or inactive eosinophilic esophagitis (EoE). The methods may include the steps of detecting whether a level of eosinophil lineage-committed progenitor (EoP) is elevated in a blood sample obtained from a subject, diagnosing the subject with active EoE when an EoP level in the sample is elevated above a pre-determined cut-off value and diagnosing the subject with inactive EoE when the EoP level in the sample is below a pre-determined cut-off value; and treating the subject diagnosed with active EoE. Kits related to same are also disclosed.

CROSS-REFERNCE TO RELATED APPLICATIONS

This application claims priority to and benefit of U.S. ProvisionalPatent Application No. 62/275,959, to Fulkerson, filed on Jan. 7, 2016,entitled “Eosinophil progenitor levels in active pediatric EosinophilicEsophagitis” in its entirety and for all purposes.

STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH

This invention was made with government support under AI093673,AI117804, and DK078392 awarded by the National Institutes of Health. Thegovernment has certain rights in the invention.

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic, food antigen-drivengastrointestinal disease characterized by marked esophagealeosinophilia. CCL26 (eotaxin-3) levels mediate eosinophil tissuerecruitment [1, 2], and eosinophil tissue counts serve as the basis fordiagnosis [3]. Currently, EoE treatment efficacy is often determined viainvasive serial endoscopies with esophageal biopsies; thus, there is acompelling need to develop novel and less-invasive blood-basedbiomarkers to evaluate EoE disease activity.

BRIEF SUMMARY

Disclosed are methods of diagnosing and treating a subject with activeor inactive eosinophilic esophagitis (EoE). The methods may include thesteps of detecting whether a level of eosinophil lineage-committedprogenitor (EoP) is elevated in a blood sample obtained from a subject,diagnosing the subject with active EoE when an EoP level in the sampleis elevated above a pre-determined cut-off value and diagnosing thesubject with inactive EoE when the EoP level in the sample is below apre-determined cut-off value; and treating the subject diagnosed withactive EoE. Kits related to same are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-1E. FIG. 1A Median absolute EoP levels in patients with activeversus inactive EoE are shown. (For all box plots, Box=25-75^(th)percentile, whiskers=minimum to maximum values, all points shown, eachpoint represents an individual patient) FIG. 1B. Median absolute EoPscorrelate with peak esophageal eosinophils (Spearman). FIG. 1C. Receiveroperating characteristic analysis of the ability of EoP levels todiscriminate between patients with and without active EoE. The soliddiagonal line indicates values that have no discriminatory value. FIG.1D. Comparison of median EoP levels in active EoE divided into twogroups, restricted diet (food trials) versus unrestricted diet, isshown. FIG. 1E. Median values of peak esophageal eosinophils in activeEoE divided into two groups, restricted diet (food trials) versusunrestricted diet, are shown.

FIG. 2. Gating strategy for EoPs. Live CD45RA-negative cells were gatedfor CD34-positive events. This population was gated for CD38 and CD125(IL-5Rα), with double-positive events being considered EoPs. EoP levelsare expressed in absolute numbers per milliliter of blood.

FIG. 3. Absolute EoPs per mL stratified by patient age are shown.Significance levels are indicated the bars span the different groups.

FIG. 4. Median of EoP levels from EoE patients with and without asthma,allergic rhinitis, or atopic dermatitis (Box=25-75^(th) percentile,whiskers=minimum to maximum values, all values shown, each circle orsquare represents an individual patient).

FIG. 5. Spearman correlation between peripheral blood eosinophils(absolute count/4) and peripheral blood EoP (absolute count/mL) isshown.

FIG. 6. Graphs showing live CD45RA, CD34, and CD38.

DETAILED DESCRIPTION

Definitions

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art. In case of conflict, the present document, includingdefinitions, will control. Preferred methods and materials are describedbelow, although methods and materials similar or equivalent to thosedescribed herein can be used in practice or testing of the presentinvention. All publications, patent applications, patents and otherreferences mentioned herein are incorporated by reference in theirentirety. The materials, methods, and examples disclosed herein areillustrative only and not intended to be limiting.

The terms and expressions used herein have the ordinary meaning as isaccorded to such terms and expressions with respect to theircorresponding respective areas of inquiry and study except wherespecific meanings have otherwise been set forth herein.

As used herein and in the appended claims, the singular forms “a,”“and,” and “the” include plural referents unless the context clearlydictates otherwise. Thus, for example, reference to “a method” includesa plurality of such methods and reference to “a dose” includes referenceto one or more doses and equivalents thereof known to those skilled inthe art, and so forth.

The term “about” or “approximately” means within an acceptable errorrange for the particular value as determined by one of ordinary skill inthe art, which will depend in part on how the value is measured ordetermined, e.g., the limitations of the measurement system. Forexample, “about” can mean within 1 or more than 1 standard deviation,per the practice in the art. Alternatively, “about” can mean a range ofup to 20%, or up to 10%, or up to 5%, or up to 1% of a given value.Alternatively, particularly with respect to biological systems orprocesses, the term can mean within an order of magnitude, preferablywithin 5-fold, and more preferably within 2-fold, of a value. Whereparticular values are described in the application and claims, unlessotherwise stated the term “about” meaning within an acceptable errorrange for the particular value should be assumed.

The terms “individual,” “host,” “subject,” and “patient” are usedinterchangeably to refer to an animal that is the object of treatment,observation and/or experiment. Generally, the term refers to a humanpatient, but the methods and compositions may be equally applicable tonon-human subjects such as other mammals. In some embodiments, the termsrefer to humans. In further embodiments, the terms may refer tochildren.

Though peripheral blood eosinophil counts moderately correlate withesophageal tissue eosinophil levels, their relationship is notsufficient to serve as a clinically useful biomarker [4]. Similar to themature eosinophil, the lineage-committed eosinophil progenitor (EoP) ismobilized during allergic disease [5]. EoP frequency is increased in theperipheral blood of adult patients with asthma in response to allergenchallenge [6, 7]. Also, EoP levels are increased in the lung tissue andsputum of allergen-challenged patients with asthma, suggesting a directcontribution to tissue eosinophilia via in situ differentiation aftermigration from the peripheral blood [6, 8]. Notably, peripheral bloodEoP levels correlate with the severity of asthma in adults, advancingthe concept of the EoP as a clinically useful biomarker [6]. No clinicalstudies to date have measured EoP levels in EoE. Applicant hypothesizedthat EoP levels would be increased in the peripheral blood of pediatricpatients with active EoE disease and would correlate sufficiently withthe level of mature eosinophils in the esophagus to serve as a relevantbiomarker for EoE disease activity. Applicants have found thatEosinophil progenitor (EoP) levels are increased in the blood ofpediatric patients with active eosinophilic esophagitis (EoE), and thatblood EoP levels can be successfully used as a novel, blood-basedbiomarker to monitor EoE disease activity.

Prior to Applicant's discovery, measurements of EoP levels in the bloodwere previously only determined in adult asthma. Measurement of EoPblood levels had never been used in EoE or in children because it wasbelieved that it would not be possible to get an accurate reading from asmall volume of blood, in the range of 5 ml or less. Applicant has foundthat, not only can a reading be obtained, but that the data obtained issurprisingly accurate.

Applicant has further found that the disclosed methods further allow formanagement of dietary control of EoE. The EoP test is a technique usingflow cytometry to identify EoPs by surface markers in a small volume ofblood and then calculate the frequency (EoP per 4) can be used todetermine when restricted foods can be reintroduced into the diet of anEoE patient. For example, if the EoP test results in an “inactivereading,” it can be determined that the permitted foods are likely notcontributing factors to EoE. Following a negative reading, the patientcan resume intake of other potentially restricted food groups, and thetest can be repeated to determine if the newly introduced foods arecontributing to EoE. Accordingly, administration of the EoE test canfacilitate management of EoE aggravated or caused by diet.

In one aspect, a method of diagnosing and treating a subject with activeor inactive eosinophilic esophagitis (EoE) is disclosed. The method maycomprise the step of detecting whether a level of eosinophillineage-committed progenitor (EoP) is elevated in a blood sampleobtained from the subject. The blood sample may have a volume of lessthan about 5, or less than about 4 or less than about 3 mLs. The subjectmay be diagnosed with active EoE when the measured EoP level in thesample is elevated above a pre-determined cut-off value or diagnosedwith inactive EoE when the EoP level in the sample is below apre-determined cut-off value. The method may further comprise the stepof treating the subject diagnosed with active EoE.

In one aspect, the pre-determined cut-off value may be about 15 EoPs permL (esophageal eosinophils/HPF) of blood, or, in certain aspects, about15.5 EoPs per mL.

In one aspect, when the EoP level is below about 15 EoPs per mL, orabout 15.5 EoPs per mL, of blood, the subject is diagnosed with inactiveEoE.

In one aspect, the treatment step may comprise administration ofsteroids, administration of a proton-pump inhibitor, withdrawal of oneor more food types, an amino-acid based formula diet, or a combinationthereof.

In one aspect, the methods may be used to identify a food sensitivity ina subject. When active EoE is diagnosed, a food type may be eliminatedfrom the diet of the subject diagnosed with active EoE. After a periodof time a second sample may be obtained from the subjectpost-elimination. If EoP is not detected, then the subject is diagnosedwith a sensitivity to the eliminated food type. The subject may betreated by placing the subject on a restricted diet. The restricted dietis typically one in which the previously-eliminated food is restrictedfrom the diet.

In one aspect, the restricted diet may be an elimination of one or morefoods selected from cow's milk, egg, soy, wheat, peanuts/tree nuts,seafood. In certain aspects, all six foods are eliminated. Guidelinesfor an elimination diet are described in Liacouras et al 2011(“Eosinophilic esophagitis: Updated consensus recommendations forchildren and adults” Liacouras, C. A., et al., Journal of Allergy andClinical Immunology, July 2011, Vol. 128, Issue 1, pp 3-20.e6, DOI:http://dx.doi.org/10.1016/j.jaci.2011.02.040). Diet therapy is describedin Warners et al 2015 (“Elimination and elemental diet therapy ineosinophilic oesophagitis,” M. J. Warners et al., ClinicalGastroenterology, October 2015, Vol. 29, Issue 5, pp 793-803, DOI:http://dx.doi.org/10.1016/j.bpg.2015.06.013.

In one aspect, a method of diagnosing and treating a subject with a foodallergy that is associated with active eosinophilic esophagitis (EoE) isdisclosed. The method may comprise the steps of

detecting whether a level of eosinophil lineage-committed progenitor(EoP) is elevated in a blood sample obtained from a subject, wherein afood has been re-introduced into the subject's diet following arestricted diet;

diagnosing the subject with a food allergy if the EoP level in thesample is elevated above a pre-determined cut-off value afterreintroduction of the previously restricted food; and

treating the subject diagnosed with the food allergy to the reintroducedfood, wherein the treatment comprises maintaining the restricted diet.

In one aspect, the pre-determined cut-off value may be about 15 EoPs permL (esophageal eosinophils/HPF) of blood.

In one aspect, where the EoP level is below about 15 EoPs per mL ofblood, the subject is diagnosed with inactive EoE.

In one aspect, a kit is disclosed. The kit may comprise a test forassaying the level of EoP in the blood of a subject; and instructionsfor diagnosing a subject with active or inactive eosinophilicesophagitis (EoE). The kit may further comprise a label instructing theuser to use the kit for diagnosis of active or inactive EoE and/or afood sensitivity.

EXAMPLES

Peripheral blood samples for EoP enumeration were obtained fromconsented pediatric patients (Table 1) undergoing endoscopy forevaluation of EoE at the Cincinnati Center for Eosinophilic Disorders(CCED, Cincinnati Children's Hospital Medical Center [CCHMC]). Includedsubjects were ages 1-18 years and had a diagnosis of EoE. Patients metthe consensus criteria for EoE and failed proton pump inhibitor (PPI)therapy, which serves as part of the diagnostic criteria of EoE [3].Patients were excluded if other inflammatory gastrointestinal diseases,such as Crohn's disease or other eosinophilic gastrointestinal diseases,were present or if they had used systemic steroids, such as prednisoneor other immune modulators, in the previous two months. Demographic andmedical record information for each participant was maintained in a CCEDresearch database and reviewed to obtain relevant patient information.

Peripheral blood mononuclear cell (PBMC) isolation and flow stainingwere performed as detailed in the online repository. EoPs wereidentified as a subpopulation of live PBMCs using the gating strategy inFIG. 2 in the online repository. Subsequently, patients were dividedinto two groups on the basis of their esophageal eosinophil levels,active EoE (n=17; median age 14.0 [interquartile range 5.5-16.5] years,peak esophageal eosinophils≧15 eosinophils/high-power microscopic field[hpf], median 52.0 [interquartile range, 36.0-86.0] eosinophils/hpf) andinactive EoE (n=14; median age 7.5 [3.0-12.5] years, peak esophagealeosinophils<15 eosinophils/hpf, median 0.5 [0.0-3.0] eosinophils/hpf).Patient age between the inactive and active disease groups was notsignificantly different (p=0.08), and median EoP levels did not vary byage (FIG. 3 in the online repository).

TABLE 1 Table I. Patient Characteristics Peak Esophageal BloodEosinophil Age^(a) Atopic Eosinophil Count Progenitor Count Sex (years)Phenotype^(b) Therapy^(c) PPI^(b) (per hpf) (per mL blood) Inactive EoE(n = 14) F 8 AR+ AD− As− Food Trials Yes 0 0 F 18 AR+ AD+ As+ FoodTrials Yes 0 6 F 9 AR+ AD− As− Food Trials Yes 0 11 M 3 AR+ AD+ As+ FoodTrials Yes 0 22 M 3 AR− AD− As− Food Trials Yes 1 18 F 6 AR+ AD+ As+Food Trials Yes 3 10 M 2 AR+ AD+ As− Food Trials Yes 2 4 M 3 AR− AD− As−Food Trials Yes 0 15 F 3 AR− AD+ As− Food Trials No 0 31 M 11 AR+ AD−As− Food Trials Yes 3 12 M 14 AR− AD− As− Food Trials Yes 1 42 F 12 AR+AD+ As− Food Trials Yes 0 41 F 7 AR+ AD+ As+ Food Trials No 4 30 M 15AR+ AD− As− Food Trials and Yes 8 0 Steroids Active EoE (n = 17) M 3 AR+AD+ As− Food Trial Yes 16 16 M 15 AR− AD− As− Food Trial No 56 35 M 7AR+ AD+ As+ Food Trial Yes 110 27 F 4 AR− AD+ As+ Food Trial Yes 23 52 F6 AR+ AD+ As+ Food Trial No 42 17 M 17 AR+ AD− As− Unrestricted Diet Yes56 45 F 17 AR+ AD+ As− Steroids Yes 49 18 M 5 AR− AD+ As− UnrestrictedDiet Yes 219 81 F 10 AR+ AD− As− Unrestricted Diet No 36 46 M 14 AR+ AD+As+ Food Trial + Yes 89 21 Steroids M 5 AR+ AD− As− Food Trial Yes 34 20M 11 AR+ AD− As− Unrestricted Diet Yes 36 41 M 17 AR+AD− As+Unrestricted Diet No 83 87 M 17 AR− AD− As− Unrestricted Diet Yes 120 44F 16 AR+ AD− As− Food Trial Yes 81 63 F 16 AR− AD− As− Unrestricted DietYes 45 37 M 16 AR+ AD− As− Unrestircted Diet No 52 37 ^(a)Age at time ofendoscopy ^(b)Per medical records; AR, allergic rhinitis; AD, atopicdermatitis; As, asthma; PPI, proton pump inhibitor ^(c)Therapy at timeof endoscopy

Identification of human EoP in peripheral blood may be performed asfollows:

Five milliliters (mL) of whole blood is collected in tubes with heparinanti-coagulant and processed immediately. Five mL of phosphate-bufferedsaline (PBS) solution is added to the whole blood and mixed gentlybefore carefully layering over Ficoll Paque Plus in a 50-mL tube. Thetube with diluted blood and Ficoll Paque Plus is centrifuged at 400×gfor 30 minutes with the brake off The interphase containing themononuclear cell layer is removed, washed in 40 mL of PBS andcentrifuged at 300×g for 10 minutes. The mononuclear cell pellet is thenresuspended in PBS (with added 0.5% bovine serum albumin and 2 mMethylenediaminetetraacetic acid) and stained at room temperature withthe following antibodies: CD45RA-APC Cy7 (final concentration 1 μg/mL),CD38-FITC (final concentration 4 μg/mL), CD34-BV421 (final concentration500 ng/uL), and CD125-PE (final concentration 2 μg/mL) and a viabilitystain. Accucount Blank Particles (50 μL per tube) were then added toeach tube. For the flow data acquisition, the beads are used as acounting gate within the SCC/FSC parameter and 10,000 events in the beadgate are acquired. Fluorescence minus one controls are utilized to setgates for flow analysis. To identify EoPs in the mononuclear cells, liveCD45RA-negative cells were gated for CD34-positive events. Thispopulation was then gated for CD38 and CD125, with double-positiveevents identified as EoPs (see FIG. 6). Absolute EoP counts per mL ofblood are determined based on number of cell events and the known numberof accucount particles in the sample volume (per manufacturer'sinstructions).

Applicant ascertained whether there were differences in blood EoP levelsin patients with active EoE disease versus inactive disease. The medianabsolute EoP level per mL of blood in patients with active EoE wasincreased more than two fold over the EoP level in patients withinactive EoE (37.0 [interquartile range, 20.5-49.0] versus 13.5[5.5-30.3] EoPs per mL of blood, p<0.001 Mann-Whitney, FIG. 1A).Absolute EoP levels also significantly correlated with the esophagealeosinophil level (Spearman r=0.56, p=0.0011, FIG. 1B). Applicant nextinvestigated the ability of EoP levels to serve as a biomarker for EoEdisease activity. A receiver operator curve showed an area under thecurve of 0.84 (95% CI, 0.70 to 0.98,p=0.0015, FIG. 1C). A cutoff valueof less than 15.5 absolute EoPs per mL accurately excluded activedisease in 100% of patients. Concurrently, levels equal to or greaterthan 15.5 absolute EoPs per mL reliably predicted active disease in 74%of patients (sensitivity=100%, specificity=57%, PPV=74%, NPV=100%,LW=2.3, LW=0). Using leave-one-out cross-validation and a threshold of15.5, Applicant found that the mean specificity was 57±3% whileretaining 100% sensitivity. These data support the utility of EoP as anexcellent disease activity biomarker in patients with EoE.

As peripheral blood EoP levels performed well as a disease activitybiomarker, Applicant assessed whether differences in EoP levels existedbetween different therapeutic groups. Both swallowed steroids andelimination diets, in which disease-triggering foods are avoided, areeffective treatments in many pediatric patients with EoE [3, 9]. Most ofthe patient cohort was on dietary therapy at the time of their endoscopy(Table 1). To investigate the effect of dietary restrictions on bloodEoP levels, Applicant subdivided the patients with active EoE diseaseinto two groups, unrestricted diet or restricted diet, at the time ofendoscopy. Applicant observed that the median absolute EoP level wassignificantly increased amongst patients with active EoE on anunrestricted diet versus those on a restricted diet (44.5 [interquartilerange, 38.0-72.3] versus 24.0 [17.8-47.8] EoPs per mL of blood, p=0.04,FIG. 1D). Interestingly, esophageal eosinophils levels were similarbetween patients with active EoE on restricted diet and those on anunrestricted diet (p=0.4, FIG. 1E), suggesting that EoP levels aresensitive to dietary restrictions in patients with active EoE disease.

As EoP levels are elevated in the peripheral blood of adult patientswith atopic diseases [5], Applicant investigated whether a history ofother allergic diseases was associated with increased blood EoP levelsin the population. A clinical history of an atopic disorder (atopicdermatitis, allergic rhinitis, or asthma) did not correlate with EoPelevations and esophageal disease activity (FIG. 2 in the onlinerepository). Additionally, peripheral blood eosinophil counts (n=10) didnot correlate with peripheral blood EoP levels (Spearman r=0.16, p=0.65,FIG. 3 in the online repository).

Thus, EoP levels may be used as a disease-monitoring biomarker inpatients previously diagnosed with EoE. The current disease monitoringstandard dictates that all patients undergo invasive endoscopy withtissue biopsies due to poor correlation between clinical symptoms andtissue inflammation [10]. Any reduction of invasive procedures throughthe use of less-invasive blood biomarkers would be valuable. Thus, inApplicant's study, 8/14 patients (57%) would have avoided endoscopy dueto correctly classified inactive disease. Such a biomarker of “diseaseinactivity” would be clinically beneficial for this population, as itmay alleviate many of the burdens associated with repeated invasiveesophageal biopsies.

REFERENCES

1. Bullock, J. Z., et al., Interplay of Adaptive Th2 Immunity withEotaxin-3/C-C Chemokine Receptor 3 in Eosinophilic Esophagitis. Journalof Pediatric Gastroenterology and Nutrition, 2007. 45: p. 22-31.

2. Blanchard, C., et al., A striking local esophageal cytokineexpression profile in eosinophilic esophagitis. J Allergy Clin Immunol,2011. 127(1): p. 208-17, 217 el-7.

3. Liacouras, C. A., et al., Eosinophilic esophagitis: updated consensusrecommendations for children and adults. J Allergy Clin Immunol, 2011.128(1): p. 3-20 e6; quiz 21-2.

4. Konikoff, M.R., et al., Potential of blood eosinophils,eosinophil-derived neurotoxin, and eotaxin-3 as biomarkers ofeosinophilic esophagitis. Clin Gastroenterol Hepatol, 2006. 4(11): p.1328-36.

5. Sehmi, R., et al., Increased Levels of CD34+ Hemopoietic ProgenitorCells in Atopic Subjects. Am J Respir Cell Mol Biol, 1996. 15: p.645-54.

6. Makowska, J., et al., Recruitment of CD34+ progenitor cells intoperipheral blood and asthma severity. Ann Allergy Asthma Immunol, 2008.101: p. 402-406.

7. Mori, Y., et al., Identification of the human eosinophillineage-committed progenitor: revision of phenotypic definition of thehuman common myeloid progenitor. J Exp Med, 2009. 206(1): p. 183-93.

8. Smith, S. G., et al., Thymic stromal lymphopoietin and IL-33 modulatemigration of hematopoietic progenitor cells in patients with allergicasthma. J Allergy Clin Immunol, 2015. 135(6): p. 1594-602.

9. Henderson, C. J., et al., Comparative dietary therapy effectivenessin remission of pediatric eosinophilic esophagitis. J Allergy ClinImmunol, 2012. 129(6): p. 1570-8.

10. Martin, L. J., et al., Pediatric Eosinophilic Esophagitis Symptom

Scores (PEESS v 2.0) identify histologic and molecular correlates of thekey clinical features of disease. J Allergy Clin Immunol, 2015. 135: p.1519-28.

All percentages and ratios are calculated by weight unless otherwiseindicated.

All percentages and ratios are calculated based on the total compositionunless otherwise indicated.

It should be understood that every maximum numerical limitation giventhroughout this specification includes every lower numerical limitation,as if such lower numerical limitations were expressly written herein.Every minimum numerical limitation given throughout this specificationwill include every higher numerical limitation, as if such highernumerical limitations were expressly written herein. Every numericalrange given throughout this specification will include every narrowernumerical range that falls within such broader numerical range, as ifsuch narrower numerical ranges were all expressly written herein.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “20 mm” is intended to mean“about 20 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A method of diagnosing and treating a subjectwith active or inactive eosinophilic esophagitis (EoE), comprising thesteps of a. detecting whether a level of eosinophil lineage-committedprogenitor (EoP) is elevated in a blood sample obtained from saidsubject; b. diagnosing said subject with active EoE when said EoP levelin the sample is elevated above a pre-determined cut-off value anddiagnosing said subject with inactive EoE when said EoP level in thesample is below a pre-determined cut-off value; and c. treating saidsubject diagnosed with active EoE.
 2. The method of claim 1, whereinsaid pre-determined cut-off value is about 15 EoPs per mL (esophagealeosinophils/HPF) of blood.
 3. The method of claim 1, wherein when saidEoP level is below about 15 EoPs per mL of blood, said subject isdiagnosed with inactive EoE.
 4. The method of claim 1, wherein saidtreatment step comprises administration of steroids, administration of aproton-pump inhibitor, withdrawal of one or more food types, anamino-acid based formula diet, or a combination thereof.
 5. The methodof claim 1, wherein, when active EoE is diagnosed, said treatment stepfurther comprises the steps of d. eliminating a food type from a diet ofsaid diagnosed subject; e. obtaining a second sample from said humansubject following step (d); f. diagnosing said subject with asensitivity to said food type when the presence of EoP above apre-determined cut-off value is not detected; and g. treating saidsubject diagnosed with a sensitivity to said food type by placing saidon a restricted diet, wherein said restricted diet excludes saideliminated food type.
 6. The method of claim 5, wherein said eliminatedfood type is one or more foods selected from cow's milk, egg, soy,wheat, peanuts/tree nuts, seafood.
 7. A method of diagnosing andtreating a subject with a food allergy that is associated with activeeosinophilic esophagitis (EoE), comprising the steps of a. detectingwhether a level of eosinophil lineage-committed progenitor (EoP) iselevated in a blood sample obtained from a subject, wherein said subjecthas re-introduced a food into said subject's diet following a restricteddiet; b. diagnosing said subject with a food allergy if said EoP levelin the sample is elevated above a pre-determined cut-off value aftersaid reintroduction of said food; and c. treating said subject diagnosedwith said food allergy to said reintroduced food, wherein said treatmentcomprises instructing said subject to adhere to said restricted diet. 8.The method of claim 7, wherein said pre-determined cut-off value isabout 15 EoPs per mL (esophageal eosinophils/HPF) of blood.
 9. Themethod of claim 7, wherein when said EoP level is below about 15 EoPsper mL of blood, said subject is diagnosed with inactive EoE.
 10. Themethod of claim 7, wherein said treatment step comprises administrationof steroids, administration of a proton-pump inhibitor, withdrawal ofone or more food types, or a combination thereof.
 11. A kit comprisinga. a test for assaying the level of EoP in the blood of a subject; andb. instructions for diagnosing a subject with active or inactiveeosinophilic esophagitis (EoE).
 12. The kit of claim 11, furthercomprising a label, wherein said label indicates that said kit is fordiagnosis of active or inactive EoE and/or a food sensitivity.